Toaru Kagaku no Railgun, Hidan no Aria AA Recommendations
Taking place in the same city but involving a new character. Hidan no Aria original characters are still present but are not the main focus. Including the main male protagonist. Same with Railgun which focuses on the other characters but not the main male protagonist. One involves science and magic (Sometimes) While other does not have any of that. Both are very action packed. There parent story was based off from a light novel. Then later on had a manga that was a spin/side story of the original light novel series.